1. Field of the Invention
The present invention relates to a stereoscopic image display apparatus and a cursor display method.
2. Description of the Related Art
In recent years, a three-dimensional video production environment is organized along with the progress in digital technologies, and three-dimensional (hereinafter “3D”) broadcast has become a reality. In a stereoscopic image display apparatus that receives and displays 3D broadcasts, a film including deflection characteristics is attached to a display panel, and video images for left eye and right eye are displayed in an interlaced format. The observer can observe a display line for left line by the left eye and a display line for right eye by the right eye through deflection glasses to stereoscopically observe the video images. There is also a stereoscopic display apparatus configured to allow the observer to stereoscopically watch the video images by alternately displaying the video images for left eye and right eye and using glasses including liquid crystal shutters to control the video images for left eye and right eye to enter only the left eye and the right eye of the observer, respectively.
Meanwhile, under the advanced satellite digital broadcast standard, a method is studied, in which an input device, such as a mouse, is used to operate the cursor other than the operation by a push-button remote control key using a conventional arrow key. In this case, the user can indicate a displayed object by a cursor operation. However, there is a problem that it is difficult to recognize which object the cursor is pointing at if a cursor of a two-dimensional plane is simply superimposed and displayed for a stereoscopic image such as 3D broadcast.
Japanese Patent Laid-Open No. 2001-326947 (hereinafter, “Document 1”) describes a technique of adding the same parallax amount as in the video image to the cursor when the cursor is displayed on a stereoscopic image to facilitate recognizing which object is indicated on the stereoscopic image. Japanese Patent Laid-Open No. 2004-354540 (hereinafter, “Document 2”) describes determining overlapping of a stereoscopically displayed object and a cursor and displaying the cursor to be stereoscopically viewed on the near side of the object when there is overlapping. Simple display of which object the cursor is indicating is also an issue in Document 2.
However, the parallax amount of the stereoscopic image at the cursor location is always applied to the cursor in the techniques described in Patent Documents 1 and 2. Therefore, the cursor may move against the user's intention when the cursor is moving. FIG. 11 is a diagram describing a trajectory when a cursor is moved using the conventional techniques. The user can recognize a plane 1302 protruding to the near side relative to a cross-point plane 1301 of parallax amount 0 (Z=0) and a plane 1303 receded to the far side. In this state, if the user attempts to operate the mouse to move the cursor from a spherical object 1304 to a spherical object 1305, the cursor also moves relative to a Z axis, which is the far side, as shown by a movement trajectory 1306 in response to the horizontal slide operation of the mouse. This is because the parallax amount of the stereoscopic image at the cursor location is applied to the cursor. As a result, the display is against the user's intended operation, and there is a problem that the user loses the sight of the cursor.